Generic road pavers or feeders, hereinafter also collectively referred to as road construction machines, are used for laying base layers, for example, concrete or asphalt layers, in the construction of roads and/or squares or for intermediate storing and transferring paving material during the paving process. The respective base layer is paved by a road paver, which is supplied with construction material for the base layer directly by a transport vehicle, for example, a truck, or via a feeder. When using a feeder, it is supplied with paving material by a transport vehicle, and transfers it via a suitable conveyor device to the road paver, which prepares the base layer. Both the paver and the feeder have a machine frame and a travel unit, for example, crawler tracks or wheels, driven by a drive unit, in most cases a diesel engine. In the operating direction of the road construction machine, it has a material hopper in the front. The operating direction refers to that direction in which the road construction machine moves during normal operation, i.e., during paving operation. The material hopper is a loading area for paving material, the size of which can be increased and/or decreased by moving and/or tilting the walls. The paving material is conveyed backwards or towards the rear from the material hopper via a conveyor device, for example, a scraper belt, through the road construction machine, where, in the case of a feeder, a conveyor device is arranged, which transfers the paving material from the feeder to the road paver. In the case of a road paver, a transverse conveyor, for example, a screw conveyor, and a paving screed are located on the rear, through which the paving material is spread across the entire paving width, smoothed, and pre-compacted. A smooth, pre-compacted base layer is left behind the road paver, which can be further compacted, for example, by rollers, in order to achieve a finished road and/or square.
The transfer of the paving material from the transport vehicle to the generic road construction machine, be it a feeder or a road paver, occurs respectively in the same way. A truck loaded with the paving material drives backwards to just in front of the road machine driving in the operating direction and then stops. A controlled collision between vehicles is then effected. For this, buffer rollers may be present, for example on the end of the road construction machine located in the front in the operating direction, which come into contact with the rear of the transport vehicle by slowly moving the road construction machine forward. The road construction machine then pushes the transport vehicle in front of it using the buffer rollers, while the paving process of the road paver is continued. The transport can then transfer the paving material, for example, by tilting the loading area backwards into the material hopper of the road construction machine arranged in the front in the operating direction. As soon as the transfer is completed, the loading area can be lowered again and the transport vehicle drives away in the forward direction.
To enable this type of material transfer from the transport vehicle to the road construction machine, the material hopper of the road construction machine cannot have any high, vertically projecting side walls in the front in the operating direction, but rather terminates relatively flatly in this area. Generic road construction machines therefore typically have a material retention device arranged on the material hopper in the front in the operating direction, which in turn comprises a fastening device and a retention element mounted on the material hopper via the fastening device. The material retention device and particularly the retention element, which is designed, for example, as a particularly flexible, elastic belt, ensure that as little as possible or ideally no paving material can fall out towards the front from the loading area of the material hopper in the operating direction of the road construction machine. The retention element therefore prevents a loss of paving material in the operating direction towards the front caused by trickling down out of the material hopper of the road construction machine. Because the material retention device is at the same time required to not obstruct the transfer of the paving material from the transport vehicle to the material hopper, the retention element is typically designed elastically, such that it may be deformed by a colliding part of the transport vehicle and can be pushed or bent to the side so that the transport vehicle can transfer the paving material without interference by the material retention device. This can be the case, for example, if the unloading transport vehicle departs from the road construction machine too soon and particularly with its loading area erected too far and still protrudes into the hopper with the lower edge of the loading area overlapping the retention device in the operating direction.
It is therefore still a problem that a large number of these loading processes are required during normal operation of the road construction machine and that sometimes, due to the transport vehicle and/or its loading area contacting the material retention device, particularly the retention element, such large tensile and/or compressive forces are exerted on the material retention device that the retention element is stripped out of the fastening devices on the material hopper and thereby destroyed. The stripped out material retention device can no longer fulfill its purpose and must be replaced. To this end, it is necessary to halt the paving with the road construction machine, remove the material retention device, and replace it with a new, intact material retention device, particularly a new retention element. The stripped-out retention elements are destroyed and must be disposed of. As a result, this increases maintenance times for replacing the retention elements. Moreover, new retention elements must be kept on hand for replacement, which complicates logistics and increases the operating costs of the road construction machine.
A generic road paver is described, for example, in DE 10 2013 000 788 A1 and a generic feeder is described in DE 10 2014 012 461 A1.
In light of the prior art, the object of the present invention is to simplify maintenance and operation of a generic road construction machine, i.e., a road paver or feeder, and to thereby save time and costs.
This object is achieved with the road paver or feeder, the material retention device, and the method according to the independent claims. Preferred embodiments are specified in the dependent claims.